

.clearfix
  display: inline-block
  &:after
    display: block
    content: "."
    height: 0
    line-height: 0
    clear: both
    visibility: hidden

//媒体查询
@media (-webkit-min-device-pixel-ratio:1.5),(min-device-pixel-ratio:1.5)
  .border-1px
    &::after
      -webkit-transform:scaleY(0.7)
      transform:scaleY(0.7)

//-webkit-min-device-pixel-ratio 有多个值，可以根据项目需求定义更多的值来适配不同的机型，详细请查看本文最后的参考
@media (-webkit-min-device-pixel-ratio:2),(min-device-pixel-ratio:2)
  .border-1px
    &::after
      -webkit-transform:scaleY(0.5)
      transform:scaleY(0.5)